Abstract: A valve control system is provided for an internal combustion engine, the engine having at least one cylinder with at least one set of at least two valves. All the valves in the set are either inlet valves or exhaust valves, and the system is configured to selectively operate the set of valves in a single valve mode of operation during which only one valve of the set is open at any time.

Abstract: An assembly for coupling a valve stem to an actuating member of an actuator in a desmodromic valve actuation mechanism comprises a spherical bearing having two portions each of which defines a respective bearing surface which is complementary to the bearing surface defined by the other portion, at least one of the surfaces being part spherical, one of the portions being arranged to be coupled to the actuating member and the other portion being arranged to be coupled to the valve stem; and a resilient arrangement which exerts a biasing force on one of the bearing portions and provides resilience in the coupling provided by the assembly between the valve stem and actuating member.

Abstract: A valve control system for an internal combustion engine, the engine having at least one cylinder with at least one intake or exhaust valve and a piston and the valve being operable independently of the rotation of the engine crankshaft. The system is configured to generate a control signal that controls a preconditioning actuation cycle of an actuator prior to a first combustion cycle of the engine, receive a feedback signal relating to an operating condition of the actuator during the preconditioning actuation cycle, and generate a modified control signal that controls a combustion actuation cycle of the actuator, modified with reference to the feedback signal. This recalibration of the valve control signals allows the current operating conditions of the valve train to be taken into account before the first combustion cycle of the engine.

Abstract: An assembly for coupling a valve stem to an actuating member of an actuator in a desmodromic valve actuation mechanism comprises a spherical bearing having two portions each of which defines a respective bearing surface which is complementary to the bearing surface defined by the other portion, at least one of the surfaces being part spherical, one of the portions being arranged to be coupled to the actuating member and the other portion being arranged to be coupled to the valve stem; and a resilient arrangement which exerts a biasing force on one of the bearing portions and provides resilience in the coupling provided by the assembly between the valve stem and actuating member.

Abstract: A valve control system is provided for an internal combustion engine, the engine having at least one cylinder with at least one set of at least two valves. All the valves in the set are either inlet valves or exhaust valves, and the system is configured to selectively operate the set of valves in a single valve mode of operation during which only one valve of the set is open at any time.

Abstract: A valve control system for an internal combustion engine, the engine having at least one cylinder with at least one intake or exhaust valve and a piston and the valve being operable independently of the rotation of the engine crankshaft. The system is configured to generate a control signal that controls a preconditioning actuation cycle of an actuator prior to a first combustion cycle of the engine, receive a feedback signal relating to an operating condition of the actuator during the preconditioning actuation cycle, and generate a modified control signal that controls a combustion actuation cycle of the actuator, modified with reference to the feedback signal. This recalibration of the valve control signals allows the current operating conditions of the valve train to be taken into account before the first combustion cycle of the engine.

Abstract: An eccentric pivot arm tensioner capable of automatic belt tensioning and substantially simultaneous operating range indexing during installation. The tensioner comprises a stop plate and cooperating lock plate. The tensioner comprises a pivot arm having a pivot arm member that cooperatively engages a base plate member. In a first, or transit mode, the pivot arm member temporarily engages the base plate member to put a torsion spring and thereby the pivot arm in a preloaded condition. The lock plate is engaged with the stop plate. As a mounting fastener is engaged into a mounting surface the pivot arm member is automatically disengaged from the base plate member by an axial movement of the pivot arm, thereby allowing the pivot arm to rotate and thereby impart a torsion spring force to a belt, i.e., tensioning the belt in an operating position.

Abstract: A tolerance compensating fastener comprising a first member having a first member bore and an outer surface having threads, a second member having a second member bore and a spherical portion engaged with the first member, a third member having threads and disposed through the first member bore and the second member bore, the third member threads engagable with a first mounting portion, a fourth member engaged between the first member and the third member, the fourth member transmits a torque from the third member to the first member whereby the first member is rotated from a second mounting portion toward the first mounting portion, and the second member disposed between the first member and the first mounting portion.